This invention relates to roller swaging of tubing such as for attaching hydraulic fitting sleeves to high strength, thin wall, aerospace hydraulic tubing. Such swaging machines are disclosed in U.S. Pat. No. 4,658,616 (Bastone) and, U.S. Pat. No. 4,793,167 (Beiley and Mikhail), both patents being assigned to the Assignee of this application. The contents of those patents are incorporated by reference herein.
In the aerospace industry, it is commonplace to attach hydraulic fittings using roller swaging of tubing. The tube to be swaged, held in place in the roller swaging machine, receives the end of an expander assembly. A sleeve to be swaged onto the tube loosely sheaths the tube. A plurality of rollers are located at the end of the expander assembly. The rollers can freely move radially toward and away from the longitudinal axis of the expander assembly. Moving along the axis of the expander assembly, a rotating tapered mandrel frictionally engages the rollers and forces the rollers against the inner wall of the tube. A strong sealed connection between the tube and the sleeve is effected as the mandrel continues to rotate and advance, causing the rollers to expand the tube, forcing the tube material to flow into grooves in the sleeve.
Prior art roller swaging exhibits the disadvantage of non-portability. Swaging machines in the prior art are too heavy and bulky for efficient and inexpensive movement onto aircraft or marinecraft to perform on-board/on-site installation and field repair.
Thus there is a need for a hand held, portable roller swaging machine which can perform on-board installation and field repair. Additionally, it would be advantageous if such a machine had light production capabilities and exhibited the benefits of both torque control and diameter control, burnishing, close control of the amount of swaging, long tool life, swaging at an overall high cycle speed, ease of use, and automatic operation.